<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <title>css3选择器</title>
    <!-- 补充代码 -->
    <style>
      a {
        color: red;
      }
      h1 {
        color: green;
      }
      h2 {
        color: blue;
      }
    </style>
  </head>
  <body>
    <!-- 补充代码 -->
    <a href="#">我是a链接1</a>
    <a href="#">我是a链接2</a>
    <a href="#">我是a链接3</a>
    <h1>我是h1标签</h1>
    <h2>我是h2标签</h2>
  </body>
</html>
